I discovered another related bug.
The Dragon Patriarch becomes hostile after exiting the conversation.
Killing the Dragon patriarch before getting the ghost spell breaks the game.
Here is the fix to prevent the Dragon Patriarch from becoming hostile after exiting the conversation.
Open the data.000 file from the savegame folder in an hex editor.
Search for the text 'patriarch153"
Ignore the first match and look for the second one which looks like this:
ASCII = "Patriarch153.....Patriarch"
HEX = "50 61 74 72 69 61 72 63 68 31 35 33 00 0A 00 00 00 50 61 74 72 69 61 72 63 68"
Overwrite the hex value for the P's with 00 so the string now looks like:
ASCII = ".atriarch153......atriarch"
HEX = "00 61 74 72 69 61 72 63 68 31 35 33 00 0A 00 00 00 00 61 74 72 69 61 72 63 68"
Save the data.000 file
Now the Dragon Patriarch no longer becomes hostile upon exiting the conversation.
